Pericardial catheter

ABSTRACT

The pericardial catheter has a main tube, flat in cross section, open at one end and closed at the other. The top wall is flat and the bottom wall is generally flat, having a plurality of openings near to but spaced from the closed end. A plurality of lengthwise extending ridges lie between successive openings and on each end of them. A round collapse-prevention member is inside the main tube and has an outer diameter at least as great as the inner distance between the top and bottom walls.

United States Patent mi 3,630,207

[72] Inventors Paul Kalm; 1,596,754 8/1926 Moschelle 128/350 Mogens L.Bramson, both of San Francisco, 3,136,316 6/ 1 964 Beall 128/350 Calif.3,430,631 3/1969 Abramson 128/350 21 AppLNo. 848,510 OTHERREFERENCESEdted t d 1 9 7 1 Miller et a1.- .lour. Thorac. & Card. Surg., Vol. 56No. 4. a en e Oct. 68, pp. 607- 608 [73] Assignee CutterLaboratories,lnc.

Berkeley, Calif. Primary Examiner Dalton L. Truluck Attorneys-BertramBradley and Owen, Wickersham &

Erickson [54] PERICARDIAL CATHETER 7 Claims, 4 Drawing Figs.

ABSTRACT: The pericardial catheter has a main tube, flat in...A6ll2I:/1;3?0R0 cross Secfion open at one end and closed at he OmenThe mp 501 Field tar 55H. Ins/348451 is and is having a rality ofopenings near to but spaced from the closed end. A plurality oflengthwise extending ridges lie between successive [56] References Citedopenings and on each end of them A round col1apse preven UNITED STATESPATENTS lion member is inside the main tube and has an outer diameter204,905 6/1878 L k 12 /349 at least as great as the inner distancebetween the top and bot- 1,045,326 11/1912 Ruflin 128/349 m llPERICARDIAL CATHETER This invention relates'to animproved pericardialcatheter or drainage tube. v v

Among the serious problems that remain in the field of surgery requiringextracorporeal circulation are intraoperative hemolysis andpostoperative tamponade.

While there are many possible causes of hemolysis, it has been foundthat one of the major causes relates to blood lying in extracardiacspaces (pericardial or pleural) for prolonged periods of time beforebeing returned to the pump oxygenator. As this blood pools, it iscontaminated by tissue fluid and fat droplets, and drying occurs at theblood-air-mernbrane junction. Further, cell tra'uma'has been found tooccur when this mixture is returned to the venous reservoirby a suctionsource that mixes great amounts of air with the blood. Together, thesefactors app'earto'be a major source of hemolysis, at least in somesystems of extracorporeal circulation. I

It has been found that these. factors can be largely eliminated by thecontinuous evacuation of the pericardial space by means of a gentlesource of suction, thereby reducing to a minimum the time for tissuefluid to mix with'the blood, for drying to occur, and for the blood andair to mix in .the cardiotomy suction. In considering these problems ofintraoperative hemolysis and postoperative tamponade, it becameapposition in the pericardium would effectively remove the blood duringthe procedure and could be placed or left in place postoperatively as ameans of dependent pericardial drainage, so longas it would not causecardiac irritability or otherwise interfere with cardiac contraction.However, fora tube to be suitable for this use, there must be means toinsure against its collapse, because if it should collapse, or ifanything should rest on it, serious problems might result.

l have found that these problems can be solved by employing a tube orcatheter which israther flat in shape, is quite flexible, and is keptopen at all times by means of a small.

round inner tube of substantially the same material and about the same.diameter, or slightly larger in minimum exterior diameter than thesmallest interior dimension of the flat tube to be used The inner tubeincluded in the lumen of the catheter prevents collapse even whenbending occurs. Another feature of the tube or catheter of my inventionis that the surface of the dependent end of the tube, which lies againstthe pericardium, has smooth, interrupted ridges; these serveto preventthe suction opening from being drawn against .the pericardium, and theyalso provide multiple channels for the progression of the blood into thecatheter. The tube or catheter is provided with a pair of generallyrectangular entrance openings on the surface having the ridges.

Further objects and advantages of the invention will appear from thefollowing description of the preferred embodiment.

ln the drawings: FIG. 1 is a bottom plan view'of a tube or catheterembodying the principles of the invention.

FIG. 2 is a view in section taken along the line 2-2 in FIG. I.

FIG. 3 is a view in section taken along the line 3-3 in FIG. 1.

FIG. 4 is a view in section taken along the line 44 in F IG. 1.

A catheter l embodying the. principles of the invention is shown in thedrawings; typically, the catheter it) may be approximately l2 incheslong, three-fourths of an inch wide, and

one-fourth of an inch thick. It comprises a flattened flexible tube 11made from a suitable plastic, such as a silicone which does notintroduce problems of infection. It should be, in

other words, inert, so far as the body fluids are concerned. The tube 11has a generally flat top surface 12 and rather shallow sidewalls l3 and14. The largest proportion of its bottom surface 15 comprises a flatportion 16, but adjacent the dependent end 17 of the tube 11 there is aplurality of ridges 20, 21, and 22 of about the proportion shown in thedrawings. Between the ridges 20 and 21 there is an entrance opening 23,and between the ridges 20 and 22 there is an entrance opening parentthat a drainage or catheter tube placed in a dependent 2s 24. Theseentrance openings 23-and 24 are preferably approximately rectangular andserve to take in the fluid. The smooth ridges 20, 21, and 22 prevent thesuction openings 23 and 24 from being drawn against the pericardium andat the same time they provide between them multiple channels 25, 26, 27,28, 29, and 30 for the progression of the blood into the openings 23'and 24.

The interior or lumen 31 of the tube ll is quite flat in cross sectionas shown in FIGS. 3 and 4 and is featured by containing an interiorcollapse-preventing tube 32 which is nominally round'in cross sectionand is preferably slightly larger in outer diameter than the interiordiameter of the lumen 31 in its narrowest direction. This tube 32 neednot be cemented in place if so made slightly larger, for it will then beheld by the natural elasticity ofthe outer flat tube 11, slightlycompressing the walls of the round tube 32, and making the-lumen 3i seekto regain its shaped and thus hold the tube 32 in place. ln place of thetube 32, a rod may be used, but a tube is better because it distortsmore easily and therefore is more easily retained in place; moreover atube 32 provides an additional lumen for suction. Cement or welding maybe used to hold the tube 32 in place, but as stated, this is usuallyunnecessary.

Wherever bending should occur, the tube 32 prevents collapse of the tube1] and even substantial weights do not collapse the tube 11 made in thismanner.

The relationship of the heart to the pericardial space is such that ifapproached by way of a median sternotomy, the oblique sinus is slightlycephalad to the angle formed by the diaphragmatic and posterior parietalpericardium. This anatomic feature thus necessitates only a very slightbend in the catheter 10 for the lowermost hole 24 to be in its dependentposition. In clinical use, it has appeared to work best if it enters thepericardial space by a stab wound in the right subcostal space justlateral to the lower end of the median sternotomy skin incision.

in clinical use, the catheter 10 is placed just as bypass is institutedand is connected by a wired connector to a cardiotomy suction source. Atthe completion of bypass it is connected to the usual chest suction andremains so during postoperative period, until drainage has ceased. it isremoved in the same way as any other chest tube.

The catheter 10 has been used on many patients without any ill effects.So long as used in the described manner, the catheter 10 does notinterfere with operative manipulations and has been noted to keep thepericardium free of blood. In the postoperative period, there has beenno evidence of cardiac irritability, the tube 11 is drained well, andthe milking of the tube 11 by the left venticular action preventsclotting. Frequently, the blood level will be seen moving back and forthwith the heart action.

To those skilled in the art to which this invention relates, manychangesin construction and widely differing embodiments and applicationsof the invention will suggest them- Selves without departing from thespirit and scope of the invention. The disclosures and the descriptionherein-are purely illustrative and are not intended to be in any senselimiting.

We claim:

l. A pericardial catheter, including in combination, a main tube offlexible plastic flat in cross section open at one end and closed at theother and having a flat top wall, a generally flat bottom wall, andshallow sidewalls, said bottom wall having entrance opening means.spaced from the closed end of the tube, said bottom wall also having aplurality of lengthwise extending ridges adjacent the longitudinal endsof said opening means, and

a collapse-prevention member, round in cross section, in-

side said main tube along the longitudinal centerline thereof and havingan outer diameter at least as great as the inner distance between saidtop and bottom walls.

2. The catheter of claim I having a plurality of entrance I openingmeans spaced apart from each other by a plurality of and slightly largerin outer diameter than the inner distance between said top and bottomwalls.

5. The catheter of claim 4 wherein said entrance openings are generallyrectangular.

6. The catheter of claim 5 wherein there are two said entrance openingsand wherein there are three said ridges in each location of said ridges.

7. The catheter of claim 6 wherein said entrance openings areapproximately as wide as the width across said ridges.

1. A pericardial catheter, including in combination, a main tube offlexible plastic, flat in cross section open at one end and closed atthe other and having a flat top wall, a generally flat bottom wall, andshallow sidewalls, said bottom wall having entrance opening means spacedfrom the closed end of the tube, said bottom wall also having aplurality of lengthwise extending ridges adjacent the longitudinal endsof said opening means, and a collapse-prevention member, round in crosssection, inside said main tube along the longitudinal centerline thereofand having an outer diameter at least as great as the inner distancebetween said top and bottom walls.
 2. The catheter of claim 1 having aplurality of entrance opening means spaced apart from each other by aplurality of lengthwise extending ridges.
 3. The catheter of claim 1wherein said collapse-prevention member is a hollow tube.
 4. Apericardial catheter, including in combination, a main flexible plastictube, flat in cross section open at one end and closed at the other andhaving a generally flat bottom wall, a flat top wall, and shallowsidewalls, said bottom wall having a plurality of entrance openingsspaced from each other and from the closed end of the tube, said bottomwall also having a plurality of lengthwise extending ridges between saidopenings and adjacent their distal ends, and a collapse-prevention tube,round in cross section inside said main tube along the longitudinalouterline thereof and slightly larger in outer diameter than the innerdistance between said top and bottom walls.
 5. The catheter of claim 4wherein said entrance openings are generally rectangular.
 6. Thecatheter of claim 5 wherein there are two said entrance openings andwherein there are three said ridges in each location of said ridges. 7.The catheter of claim 6 wherein said entrance openings are approximatelyas wide as the width across said ridges.